Cleaning tool for a connecting end face of an optical connecting part and method

ABSTRACT

A connecting end face cleaning tool having superior cleaning properties includes a cleaning fabric. This cleaning tool removes soiling attached to the connecting end face of an optical connecting part when that connecting end face is detached. The cleaning fabric is constructed such that the woof threads protrude from the surface of the fabric more than the warp threads. The cleaning fabric has a tape-like shape, the lengthwise direction of which is the direction of the extension of the warp threads. Soiling is removed from a connecting end face as the connecting end face and cleaning fabric are moved relatively such that the connecting end face moves transverse to the woof threads of the cleaning fabric. A method of cleaning a connecting end face uses a cleaning fabric with woof threads protruding from the surface of the fabric more than the warp threads and the fabric is moved relative to the connecting end face transverse to the woof threads of the fabric.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2003-410928 filed on Dec. 9, 2003, theentire content of which is incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning tool for the connecting endface of an optical connecting part, used for removing any soiling orattached matter present on the connecting end face of a frequentlyconnected and disconnected optical connector or the like. The inventionalso relates to a method of cleaning the connecting end face of anoptical connecting part.

2. Description of Related Art

Optical connectors incorporated in equipment used for opticaltransmission are frequently connected and disconnected. For this reason,dust or oils and the like may become attached to the end face of anoptical connector when the connector is disconnected, causing adeterioration in the transmission properties of the connector. In orderto prevent this problem, the connecting end face of an optical connectoris cleaned when the optical connector is disconnected.

Cleaning tools for cleaning the connecting end face of an opticalconnector include cleaning tools for a male type connector having anexposed connecting end face of a ferrule and cleaning tools for a femaletype connector in which the connecting face to be cleaned is enclosed inan adapter as in an optical connector incorporated in a switchboard orthe like. A variety of different types of cleaning tools have beenproposed for these two types of optical connectors.

For example, there are cleaning tools for cleaning a male typeconnecting end face that operate by pressing the connecting face of aferrule against the surface of a cleaning tape and moving the connectingend face relative to the cleaning tape to perform cleaning. The cleaningtool disclosed in Japanese Unexamined Patent Application Publication No.2003-200116 operates by bringing the connecting end face of a ferruleinto contact with the surface of a running cleaning tape for cleaning.

Further, cleaning tools for cleaning the end face of a female typeconnector include tools such as the cleaning tool disclosed in JapanesePatent No. 3,350,850. In that cleaning tool, a cleaning part comprises ahousing having an engaging part that engages an optical connector. Thecleaning tool is inserted in the optical connector and the connectingend face is cleaned by running a cleaning tape exposed from the end partof the cleaning part. Also disclosed is a cleaning tool in whichcleaning tape is brought into contact with the connecting end face andthen rotated to clean the connecting end face.

Cleaning tools that are used to clean a connecting end face by movingcleaning tape in relation to the connecting end face generally employnon-woven fabric or plain woven (flat woven) fabric having nodirectionality.

SUMMARY OF THE INVENTION

As a result of investigating the effects on the cleaning properties offabric having no directionality and other fabrics used in theconventional cleaning tape of cleaning tools for cleaning the connectingend face of an optical connecting part as described above, the inventorof the present invention discovered that there are differences incleaning properties according to the different types of fabric used.

An object of the present invention is to determine the relationshipbetween cleaning properties and the type of cleaning fabric used in acleaning tool for cleaning the end face of an optical connecting part soas to provide an end face-cleaning tool for an optical connecting parthaving superior cleaning properties.

In order to achieve the above objective, according to one aspect of thepresent invention, a cleaning tool for the end face of an opticalconnecting part is provided comprising a cleaning fabric made of wovenfabric having a surface and woof and warp threads, the woof threadsprotruding out more from the surface of the fabric than the warpthreads, said cleaning fabric having a tape-like form, the lengthwisedirection of which is the direction of the extension of said warpthreads.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

These and other objects, features and advantages will become clearerfrom the following description of exemplary embodiments of theinvention, read in connection with the accompanying drawings in which:

FIG. 1 is a schematic plan view of a connecting end face cleaning toolformed in a tape-like shape according to the present invention;

FIG. 2A and FIG. 2B are respectively, a structural view and a schematicview of plain woven fabric;

FIG. 3A and FIG. 3B are respectively, a structural view and a schematicview of twill woven fabric;

FIG. 4A and FIG. 4B are respectively, a structural view and a schematicview of satin woven fabric;

FIG. 5 is an actual photograph of satin woven fabric in which the woofthreads protrude from the fabric surface more than the warp threads;

FIG. 6 shows the results of a cleaning experiment performed on a maletype connecting end face using plain woven fabric cleaning tape;

FIG. 7 shows the results of a cleaning experiment performed on a maletype connecting end face using twill woven fabric cleaning tape;

FIG. 8 shows the results of a cleaning experiment performed on a maletype connecting end face using satin woven fabric cleaning tape;

FIG. 9 shows the results of a cleaning experiment performed on a maletype connecting end face using twill woven fabric cleaning tape andmoving the connecting end face along the direction of the woof threadsof the cleaning tape;

FIG. 10 shows the results of a cleaning experiment performed on a maletype connecting end face using satin woven fabric cleaning tape andmoving the connecting end face along the direction of the woof threadsof the cleaning tape;

FIG. 11 shows the results of a cleaning experiment performed on a femaletype connecting end face using plain woven fabric cleaning tape fittedinto a cleaning device;

FIG. 12 shows the results of a cleaning experiment performed on a femaletype connecting end face using twill woven fabric cleaning tape fittedinto a cleaning device;

FIG. 13 shows the results of a cleaning experiment performed on a femaletype connecting end face using satin woven fabric cleaning tape fittedinto a cleaning device;

FIG. 14 is a schematic view showing the cleaning of a male typeconnecting end face using a cleaning fabric; and

FIG. 15 is a schematic view showing the cleaning of a female typeconnecting end face using a cleaning fabric.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments of the invention are described below withreference to the accompanying drawings. The described exemplaryembodiments are intended to assist the understanding of the invention,and are not intended to limit the scope of the invention in any way. Inthe drawings, like reference numerals identify like elements.

An embodiment of the present invention will now be described withreference to FIGS. 1 to 15.

FIG. 1 is a schematic plan view of a cleaning fabric for a connectingend face-cleaning tool formed in a tape-like shape according to thepresent invention.

In FIG. 1, a connecting end face-cleaning tool 1 comprises a cleaningfabric 3 made of woven fabric having a surface in which the woof threadsprotrude out further in relation to the warp threads. More specifically,thread comprised of a plurality of thick fibers is used for the warp ofthe woven fabric and thread comprised of a plurality of fibers that arethin in comparison to the fibers of the warp is used for the woof. It ispreferable that the diameter of each of the fibers of the warp threadsis 15 μm or greater and that the diameter of each of the fibers of thewoof threads is 2 μm or less.

This fabric 3 may be plain woven, twill woven or satin woven.

FIG. 2A shows a structure of plain woven fabric. In this plain wovenfabric, each of the woof threads 7 passes alternately over and undereach of the warp threads 5 and each of the warp threads 5 passesalternately over and under each of the woof threads 7.

FIG. 2B shows a schematic view of the plain woven fabric shown in FIG.2A. As shown in FIG. 2B, in the plain woven fabric, the woof threads 7are exposed on the surface of the fabric at the same ratio as the warpthreads 5. Accordingly, if thread of the same diameter and comprised offibers of the same diameter as that of the warp threads 5 is used forthe woof threads 7, the ratio of protrusion on the surface of the fabricof the woof threads 7 is the same as that of the warp threads 5.However, if threads of the same diameter as that of the warp threads 5and comprised of finer fibers is used for the woof threads 7, the woofthreads protrude further on the surface of the fabric than the warpthreads because the bulk density of the threads decreases as thediameter of the fibers becomes smaller.

FIG. 3A shows an exemplary structure of twill woven fabric. In the twillwoven fabric shown in FIG. 3A, each of the woof threads 7 passesalternately over and under each grouping of four of the warp threads 5and each of the warp threads 5 passes alternately over and under eachgrouping of two of the woof threads 7.

FIG. 3B shows a schematic view of the twill woven fabric shown in FIG.3A. As shown in FIG. 3B, in the same manner as the plain woven fabric,in this twill woven fabric the woof threads 7 are exposed on the surfaceof the fabric at the same ratio as the warp thread 5. Accordingly, ifthread of the same diameter and comprised of fibers of the same diameteras that of the warp threads 5 is used for the woof threads 7, the ratioof protrusion on the surface of the fabric of the woof threads 7 is thesame as that of the warp threads 5. However, if thread of the samediameter as that of the warp threads 5 and comprised of finer fibers isused for the woof threads 7, in the same manner as the plain wovenfabric, the woof threads protrude further on the surface of the fabricthan the warp threads because the bulk density of the thread decreasesas the diameter of the fibers becomes smaller.

FIG. 4A shows an exemplary structure of satin woven fabric. In thissatin woven fabric shown in FIG. 4A, each of the woof threads 7 passesalternately over a grouping of four warp threads 5 then under one warpthread 5 and each of the warp threads 5 passes alternately under agrouping of four of the woof threads 7 and over one of the woof threads7.

FIG. 4B shows a schematic view of the satin woven fabric shown in FIG.4A. As shown in FIG. 4B, in this satin woven fabric the woof threads 7are exposed on the surface in a greater proportion than the warp threads5. Accordingly, even when thread of the same diameter and comprised offibers of the same diameter as that of the warp thread 5 is used for thewoof thread 7, the ratio of protrusion on the surface of the fabric ofthe woof threads 7 is greater than that of the warp threads 5.

FIG. 5 shows a typical example of satin woven fabric. This satin wovenfabric is woven using warp threads comprised of fibers of 15 μm diameterand woof threads of the same diameter as the warp threads and comprisedof fine fibers of 2 μm diameter. Because the fabric is woven using thewoof threads comprised of finer fibers than that of the warp threads,the fibers of the woof threads protrude out over the entire surface ofthe fabric greater than the warp threads.

Cleaning fabric 3 structured as described above is cut out in atape-like shape such that the direction of the extension of the warpthreads 5 is in the lengthwise direction of the fabric. Here, cut edges1 a and 1 b each providing a clean edge with no fluffiness can beobtained by a cutting process that cuts the fibers using heat, such asultrasonic cutting or thermal cutting.

Formed in this way, the tape-shaped cleaning fabric 3 for the connectingend face cleaning tool 1 is used, when cleaning a male type connectingend face 9 a (FIG. 14) of an optical connecting part 9, by running thecleaning fabric 3 along the surface of a supporting base 10 and pressingthe connecting end face 9 a vertically downwardly onto the surface ofthe cleaning fabric 3. In this way, the connecting end face 9 a isrubbed by the woof threads 7 of the cleaning fabric 3 thereby removingsoiling on the connecting end face 9 a.

As the woof threads 7 protrude more on the surface of the cleaningfabric 3 than the warp threads 5 in the connecting end face cleaningtool 1, a connecting end face 9 a being cleaned is rubbed withsubstantial frictional force, thereby facilitating efficient removal ofsoiling on the end face being cleaned. Further, as the woof thread 7 iscomprised of fine fibers even very small particles of soiling on theconnecting end face can be easily removed.

In summary, this embodiment of the connecting end face cleaning tool 1according to the present invention has the following characteristics.

Firstly, the cleaning fabric is woven of warp threads comprised of aplurality of thick fibers and woof threads comprised of a plurality offine fibers, the woof threads protruding on the surface of the cleaningfabric to a greater extent than the warp threads.

Secondly, the cleaning fabric can be plain woven, twill woven or satinwoven fabric.

Thirdly, threads comprised of extremely fine fibers having a diameter of2 μm or less are used for the woof threads.

Fourthly, as the cleaning fabric is subject to either ultrasonic cuttingor thermal cutting such that the direction in which the warp threadsextend is the lengthwise direction of the fabric, the cleaning fabric isa tape-like form having a clean edge with no fluffiness.

According to the above-described connecting end face cleaning tool 1,soiling and attached substances can be effectively removed from aconnecting end face being cleaned. A clean connecting end face canthereby be obtained as the connecting end face being cleaned is movedrelative to the fabric so in a direction transverse to the woof threadsof the fabric in which the woof threads protrude on the surface to agreater extent than the warp threads.

EXAMPLE 1

An assessment of the cleaning properties of the above-described cleaningtape 3 was conducted in relation to a connecting end face 9 a of a maletype connector 9 as shown in FIG. 14. More specifically, to assess thecleaning properties of the cleaning tape 3, reflection loss was measured30 times before soiling was applied to the connecting end face 9 a,after soiling was applied to the connecting end face 9 a and aftercleaning the connecting end face 9 a with the cleaning tape 3. Soilingwas applied according to Bellcore (previously Bell Labs) standardGR-2923-CORE 5.1.4 to the connecting end face 9 a. Cleaning of theconnecting end face 9 a was conducted by relative displacement of 50 mmof the connecting end face in the lengthwise direction of the cleaningtape 3, that is to say, in the direction transverse to the woof of thetape, while the connecting end face 9 a was pressed to the cleaning tape3.

FIG. 6 shows the results of 30 measurements obtained when using plainwoven cleaning tape woven of warp threads and woof threads that wereboth of fibers of a diameter of 2 μm. FIGS. 7 and 8 show respectively,the results of 30 measurements when using cleaning tape employing twillwoven and satin woven fabric in which the woof threads protrude to agreater extent on the surface of the cleaning tape than the warpthreads, the warp threads being of fibers of a diameter of 15 μm and thewoof threads being of fibers of a diameter of 2 μm.

As shown in FIGS. 6, 7 and 8, the average values of reflection lossobtained for the 30 measurements performed after cleaning were 47 dBwhen using plain woven cleaning tape and 52 dB when using satin woven ortwill woven cleaning tape. Accordingly, superior cleaning effects wereobtained from the satin woven or twill woven cleaning tape in contrastto the plain woven cleaning tape. Further, soiling was removed by thesatin woven and twill woven fabric tapes to create a substantially cleancondition in which the average reflection loss was close to the averagereflection loss of 55 dB obtained for the 30 measurements conductedprior to application of soiling.

FIGS. 9 and 10 show respectively the results obtained using twill wovenand satin woven fabric tapes, both cleaning the connecting end face 9 aby relative displacement of 50 mm of the connecting end face in thelengthwise direction of the woof threads 7 of the respective tapes. Asshown in FIGS. 9 and 10, the average values for reflection loss aftercleaning were 45 dB in both cases, indicating that cleaningeffectiveness was obtained only at about the same level of as that ofthe plain woven fabric 3 shown in FIG. 6.

EXAMPLE 2

An assessment of the cleaning properties of the cleaning tapes 3 wasalso conducted for a female type connector. More specifically, in thesame manner as for Example 1, reflection loss of the connecting end face9 a was measured 30 times before soiling was applied to the connectingend face 9 a, after soiling was applied to the connecting end face 9 aand after cleaning the connecting end face 9 a with the cleaning tape 3.Soiling was applied according to Bellcore (previously Bell Labs)standard GR-2923-CORE 5.1.4 to the connecting end face 9 a.

For cleaning the connecting end face 9 a of the female connector 9, acleaner 11 having an operating part 15 shown in FIG. 15 and disclosed inJapanese Unpublished Patent Application No. 2003-293006 (InternationalApplication No. PCT/JP2004/009830) was used. In the same manner asExample 1, plain woven, twill woven or satin woven fabric tape 3 wasused, this being disposed in the cleaner 11 such that the respectivefabrics were exposed from the tip of the cleaning part 13. This cleaningpart 13 was inserted in the connector 9 and the cleaning end face 9 awas cleaned by rotating the cleaning tape 10 mm while making contactwith the connecting face 9 a.

FIGS. 11 to 13 show the results measured when cleaning using the threetypes of cleaning tape 3, respectively, the plain woven, twill woven andsatin woven fabric cleaning tapes. As shown in those figures, in thesame manner as the results for the male type connectors, in comparisonto the plain woven fabric tape that has no directionality, superiorcleaning effects were obtained from the satin woven or twill wovencleaning tapes in which the woof threads protrude from the surface ofthe fabric to a greater extent than the warp threads.

Although the invention has been described above by reference to certainexemplary embodiments of the invention, the invention is not limited tothe embodiments described above. Modifications and variations of theembodiments described above will occur to those skilled in the art, inlight of the above teachings. The scope of the invention is defined withreference to the following claims.

1. A connecting end face cleaning tool for an optical connecting partcomprising a cleaning fabric made of woven fabric having a surface andwoof and warp threads, the woof threads protruding out more from thesurface of the fabric than the warp threads, said cleaning fabric havinga tape-like form, the lengthwise direction of which is the direction ofthe extension of said warp threads.
 2. The connecting end face cleaningtool according to claim 1, wherein said cleaning fabric is woven of warpthreads comprised of a plurality of fibers and woof threads comprised ofa plurality of fibers that are finer than the fibers of said warpthreads.
 3. The connecting end face cleaning tool according to claim 1,wherein said cleaning fabric is one of plain woven, twill woven or satinwoven.
 4. The connecting end face cleaning tool according to claim 1,wherein said woof threads comprise fibers having a diameter of 2 μm orless.
 5. The connecting end face cleaning tool according to claim 1,wherein the tape-like form of said cleaning fabric has a cut edge cut byultrasonic or thermal cutting.
 6. The connecting end face cleaning toolaccording to claim 1, wherein said woof threads comprise fibers having adiameter of 2 μm or less and said warp threads comprise fibers having adiameter of 15 μm or greater.
 7. The connecting end face cleaning toolaccording to claim 1, wherein the optical connecting part is a male typeconnector.
 8. The connecting end face cleaning tool according to claim1, wherein the optical connecting part is a female type connector. 9-11.(canceled)